Both fear discrimination and extinction probe fear and safety using learned stimuli, but a true safety signal should also apply to innate behavior. To probe safety in an innate anxiety paradigm, we evaluated data from the same animals prior to fear conditioning in a brightly lit open field. Most mice tend to avoid the center, staying near the walls of the periphery, while some mice actively explore the entire environment (Figure 8D). We evaluated changes in fast gamma for both anxious (<10% center time, n=9) and non-anxious (>10% center time, n=6) animals (defined as in Likhtik et al., 2014). As expected, a safety-related increase in fast gamma power was observed only in anxious mice as they moved further from the anxiogenic center (Figure 8E; p=.003, MLR, zone vs. fast gamma power; non-anxious mice, p=.463). As during fear conditioning, we found enhanced mPFC Granger lead strength towards the periphery for anxious mice (Figure 8F; p=.026, MLR) but not non-anxious mice (p=.565). It is notable that anxious and non-anxious animals were equally likely to go on to be discriminators (56% and 66%,
